From: LARRY KLAES (ljk4_at_msn.com)
Date: Fri Oct 12 2007 - 06:15:02 PDT
>From: "AAS Press Officer Dr. Steve Maran" <Steve.Maran_at_aas.org>
>To: "AAS Press Officer Dr. Steve Maran" <steve.maran_at_aas.org>
>Subject: U Hawaii Manoa: Look to the horizon of future planet searches
>Date: Thu, 11 Oct 2007 10:55:12 -0400
>
THE FOLLOWING RELEASE WAS RECEIVED FROM THE UNIVERSITY OF HAWAII AT MANOA,
IN HONOLULU, AND IS FORWARDED FOR YOUR INFORMATION. (FORWARDING DOES NOT
IMPLY ENDORSEMENT BY THE AMERICAN ASTRONOMICAL SOCIETY.) Steve Maran,
American Astronomical Society steve.maran_at_aas.org 1-202-328-2010 x116
EMBARGOED
Not for public release until Thurs. Oct. 11, 2 p.m. EDT
Contact:
Eric Gaidos
Geology and Geophysics, SOEST
1-510- 643-9943
Nader Haghighipour
Institute for Astronomy
1-808-956-6880
PIO Source:
Arlene Abiang
Public Information Officer
Tel: 1-808-956-5637
Fax: 1-808-956-6917
abiang_at_hawaii.edu
UH Manoa researchers look to the horizon of future planet searches
HONOLULU - In a paper published this week in the journal Science, three
University of Hawaii at Manoa researchers and their colleagues review the
prospects for discovering smaller planets more like Earth, some of which may
even have conditions suitable for life. Astronomers reported the first
planet around another Sun-like star in 1995 and since then have found more
than 200 such planets, all thought to be “gas giants” made mostly of
hydrogen and helium like Jupiter and Saturn in our Solar System.
“The most successful technique for discovering planets to date spreads
light from the host star into its constitutive wavelengths (colors)” said
lead author Eric Gaidos, who is an associate professor in the Department of
Geology & Geophysics and the NASA Astrobiology Institute at UH Manoa. “A
shift in wavelength, analogous to the change in pitch of the horn of a
passing automobile, reveals any motion of the star along the line of sight.
Monitoring of a star can detect periodic motion caused by the gravitational
pull of any unseen, orbiting planet.”
Improved techniques and the ability to monitor fainter stars now enable
astronomers to discover smaller planets, particularly planets orbiting much
closer to their host star than the Earth is to the Sun. New computer
simulations such as those performed by Sean Raymond, co-author of the paper
and NASA Postdoctoral Fellow at the University of Colorado Boulder, show how
such planets could form further out and then “migrate” inwards to such
orbits.
Another method now used to find planets is to observe the slight decrease in
light from the star as an orbiting planet passes in front of it. This
happens only for those planets whose orbits by chance are seen edge-on.
Jupiter-sized planets can be found this way using telescopes on the ground,
but Earth-size planets might be detected by the European CoRoT spacecraft,
now in orbit, and NASA’s Kepler spacecraft, scheduled to launch in 2009.
“These methods can sometimes be combined to estimate the density of the
planet, which will tell us whether the planet is composed mostly of rock and
metal, like Earth, or something else such as water ice,” said Gaidos.
Computational simulations by co-author Nader Haghighipour, a planetary
dynamicist at the Institute for Astronomy and the Astrobiology Institute at
UH Manoa, have shown that smaller Earth-sized planets can indeed exist in
such tight planetary environments.
According to the paper, planets orbiting much closer to a star like the Sun
will be much hotter and, like Mercury and Venus in our Solar System,
inhospitable to life. However, many stars are much less bright than the
Sun, and planets close to them could still orbit within a “habitable
zone” where surface temperatures could permit stable liquid water.
“Explaining the formation of habitable planets in such environments is a
challenging task. However, our simulations have been successful in
determining condition under which planets similar to Earth can form in the
habitable zones of less bright stars,” said Haghighipour.
Future space observatories beginning with NASA’s James Webb Space
Telescope have the potential to study such planets and determine whether
they have atmospheres or oceans.
Added Gaidos, “The discovery of another life-bearing planet would be a
scientific triumph for humanity, but the study of many lifeless, un-Earthly
worlds would nevertheless tell us about how planets form, and help us
appreciate the Earth all that much more”.
Other researchers contributing to the paper were John Rayner of the
Institute for Astronomy at UH Manoa, Eric Agol of the University of
Washington and David Latham of the Harvard-Smithsonian Center for
Astrophysics.
MEDIA NOTE:
To obtain a copy of the Science paper and supplemental images, contact the
AAAS Office of Public Programs. A list of staff contacts can be found at:
http://www.eurekalert.org/pio/sci/index.php?page=staff.
###
ABOUT THE SCHOOL OF OCEAN AND EARTH SCIENCE AND TECHNOLOGY
The School of Ocean and Earth Science and Technology (SOEST) was established
by the Board of Regents of the University of Hawaii in 1988. SOEST brings
together in a single focused ocean, earth sciences and technology group,
some of the nation’s highest quality academic departments, research
institutes, federal cooperative programs, and support facilities to meet
challenges in the ocean and earth sciences, including the Hawaii Institute
of Geophysics and Planetology (HIGP). Scientists at SOEST are supported by
both state and federal funds as they endeavor to understand the subtle and
complex interrelations of the seas, the atmosphere, and the earth. For more
information, visit www.soest.hawaii.edu
ABOUT THE INSTITUTE FOR ASTRONOMY
Founded in 1967, the Institute for Astronomy at the University of Hawaii at
Manoa conducts research into galaxies, cosmology, stars, planets, and the
sun. Its faculty and staff are also involved in astronomy education, deep
space missions, and in the development and management of the observatories
on Haleakala and Mauna Kea. For more information, visit
http://www.ifa.hawaii.edu/
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